<spoiler> I really enjoyed the story (pretty sure I've read it before, but many years ago, so it's fuzzy) and I know it's not key to the plot, but I really want to know how Jack failed to survive.
It is implied in the beginning: he expects to die before the singularity because of a tendency of heart problems in their family.
It is implied in the beginning: he expects to die before the singularity because of a tendency of heart problems in their family.